JPS6011320A - Method of molding hole in composite material - Google Patents

Abstract

PURPOSE:To form fastener holes at low cost with high quality, by carrying out at the same time the fitting of pins into a composite material by a compression force and the molding of holes when the composite material of fiber and resin is compression molded. CONSTITUTION:A molding material 5 comprising a prescribed number of layers together with a bleeder cloth 6 for regulating the quantity of resin is previously sandwiched between templates 2 that have guide holes at required positions, and after pins 1 are inserted in the guide holes, they are set to a base plate 4 by using a dam 3 as a reference. Then after all of them are covered with a vacuum film 7, the compacting of fibers and the regulating of the quantity of resin are carried out simultaneously by heating under vacuum, and the pins are fitted by using the vacuum. Then they are turned and put on a base plate 4, and all of them are covered with a vacuum film 7, and is heated under pressure to obtain a composite material having fastener holes.

Description

Detailed Description of the Invention The present invention relates to composite paulownia wood products having automatically formed fastener holes, circular holes such as bearing holes, and polygonal holes such as square and hexagonal holes, such as structural parts for aerospace equipment, In addition to composite materials that can be applied to transportation equipment, automobiles, general industrial equipment, electrical and electronic parts, etc., and composite materials for special needs such as carbon fiber/epoxy and Kevlar fiber/epoxy, fiber-reinforced composite shrines commonly referred to as FRP. This invention relates to a ball forming method that can be applied to ball forming almost all composite materials such as materials.

Conventionally, the most common method for preparing fastener balls, etc. for mating materials is to use a cutting tool such as a drill or reamer to place a fastener of a desired size on a composite material formed into an arbitrary shape. This was a method of mechanically processing balls and the like.

However, this method requires two steps: molding and one-snare processing, which has the disadvantage of increasing the number of manufacturing steps.
In addition, if the reinforcing fiber is an ultra-hard material such as carbon fiber, the cutting force of the cutting tool itself will be significantly reduced due to its hardness, which will increase the cost of preparing the number of drills and the cost of re-grinding. There was a drawback.

Furthermore, when high quality is required for the inner surface of fastener holes such as aircraft parts, defects on the inner surface of fastener holes due to secondary processing with cutting tools, such as resin burning due to cutting heat, etc., and peeling between the eyebrows due to cutting stress, etc. There was a risk of such occurrence.

The object of the present invention is to process a fastener for a composite material such as carbon fiber/epoxy resin at low cost and with high quality.

That is, the present invention provides a method for forming fastener holes, etc. in a composite material such as carbon fiber/epoxy, in which a pin having a desired fastener shape is inserted into the composite material using molding pressure while the composite material is in a flexible state. The feature is that the fastener hole is automatically formed by drilling the holes and then curing them.In particular, by processing the fastener balls of composite materials in one step, the cost is lower in terms of man-hours and tools than the conventional two-step process. The present invention aims to provide a hole forming method for a composite material that can simultaneously form a counterbore, a single step hole, etc. by considering the shape of the pin.

Embodiments of the present invention will be described below with reference to the drawings. FIGS. 1 to 4 show an example of automatic fastener hole forming according to an embodiment of the present invention. In the figure, the molding jig has a mold-released steel pin 1 and a guide hole for the pin 1, and is made of composite paulownia wood or ceramic in order to accurately mold the pin into the specified position, and the receiver can also be made of rubber on the side. It consists of a template 1-2, an aluminum dam 3, and a steel or aluminum base plate 4.

Figure 1 shows the state in which the molding material 5 sandwiched by the template 2 and the pin 1 are set on the base plates 1 to 4, and Figure 2 shows the pin 1 being molded by vacuum pressure during the fiber densification process. How the minutes go into material 5,
FIG. 3 shows the hardening process with the pin 1 penetrating the molding material 5. Moreover, FIG. 4 shows a situation in which various fastener holes can be formed by changing the shape of the pin.

The present invention relates to a method of preparing a fastener ball or the like of a composite material with a low 21st stroke and high quality by simultaneously molding it in a molding and curing process, and the molding method will be described below.

First, in FIG. 1, a predetermined number of laminated molding materials 5 are sandwiched together with a bleeder cloth 6 for adjusting the amount of resin between templates 2 that have guide holes at required hole positions, and pins 1 are inserted into the guide holes. After inserting the base plate 4
cents based on Dam 3.

Next, in Fig. 2, after covering the entire body with a vacuum film 7, the fibers are densified and the amount of resin is adjusted by heating and reducing the pressure.
The pins are inserted between the Ji fibers using reduced pressure to complete the preparation for main curing.

Further, the laminate which has undergone the fiber densification process is then turned over as shown in Figure 3, placed on the base plate 4, covered again with the vacuum film 7, and then heated and pressurized to perform main curing. It can be done. After the final curing, all molding jigs are removed from the case layer body, which becomes a composite material with fastener balls and the like.

By using the automatic forming method for fastener holes, etc. of the present invention, the forming process, which was conventionally performed in two steps, is reduced to step 1, resulting in low-cost production such as shortening the forming process time and reducing the number of tools used. In addition to this, it is possible to obtain effects such as eliminating defects on the inner surface of the fastener ball caused by machining of the fastener ball.

[Brief explanation of the drawing]

1, 2 and 3 are sectional views showing an automatic fastener forming method showing embodiments of the present invention in different operating states, and FIGS. and FIG. 1 is a W1 side view showing the case of a stepped hole. Explanation of the main parts of the diagram 1 - Pin 2 - Template 3 - Dam 4 - Base play 1, 5 - Molding material Patent applicant Mitsubishi Heavy Industries, Ltd. Figure 3

Claims (1)

[Claims] 1. A method for forming holes in a composite material, characterized in that when compression molding a composite material made of fibers and fat, a bottle is inserted into the composite material by compression force to mold a ball at the same time.